Method for producing adhesive carpet pads

ABSTRACT

A carpet pad has pressure sensitive adhesive preapplied on one or both surfaces, for retaining the pad and a carpet in place on a floor by adhesion without the need for stretching. The pad or cushion in one embodiment has a film or sealant on the surfaces of the pad, with pressure sensitive adhesive on at least one of the sealed surfaces for adhering to floor surface or the underside of a carpet. In another embodiment, the pressure sensitive adhesive is a hot melt adhesive, not water-based. The hot melt pressure sensitive adhesive is applied to an uncoated porous padding surface which would be unsuitable for a water-based pressure sensitive adhesive due to excessive wicking-in of such an adhesive. An optional scrim webbing may be applied over the pressure sensitive adhesive, in either embodiment. The scrim webbing adds dimensional stability and also enables the carpet pad to be moved around on a floor or against another surface without sticking, prior to the application of pressure.

REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 243,606, filedSep. 13, 1988, now U.S. Pat. No. 5,160,770, which was acontinuation-in-part of application Ser. No. 882,173, filed July 7,1986, now U.S. Pat. No. 4,797,170 and of application Ser. No. 147,214,filed Jan. 22, 1988, now abandoned.

BACKGROUND OF THE INVENTION

This application relates to a carpet pad and system for holding a carpetin place without stretching. The system is of the general typeillustrated and described in U.S. Pat. No. 4,557,774, issued Dec. 10,1985 to the same inventor and assignee as this application.

The system of the present invention involves a carpet cushion which hasa pressure sensitive adhesive preapplied to one surface of the cushionor padding, as opposed to U.S. Pat. No. 4,557,774, which disclosedpressure sensitive adhesives preapplied to both surfaces. U.S. Pat. No.4,557,774 is hereby incorporated in this disclosure by reference.

The present invention also relates to carpet pads or cushions having ahot melt pressure sensitive adhesive applied to an otherwise uncoatedand unsealed porous padding surface which would be unsuitable for awater based pressure sensitive adhesive. On such porous surfaces, waterbased adhesives tend to wick excessively into unsealed porous surfaces.

Conventionally, carpeting has been installed on floors in severaldifferent ways. In the conventional tackless strip system, the so-calledtackless strip is secured to the floor around the walls of the room, thecarpet is hooked onto the upwardly protruding nails of the tacklessstrip at one side of the room, and the carpet is stretched before it ishooked to the tackless strip at the opposite side of the room. Oneproblem with this system is that it requires the installation of thetackless strip, which is time-consuming and which is difficult whenconcrete floors are encountered. Another problem is that it requires atrained professional to re-stretch the carpet in the event a corner oredge portion of the carpet needs to be temporarily taken up, access tothe floor or for drying a carpet which has been wetted.

Many carpet installations involve gluing of the carpeting to the floor,without any carpet cushion or pad between the carpet and the floor. Withsuch an installation, the carpeting can be of less expensiveconstruction, with a primary backing but without the need for asecondary backing (jute or polypropylene backing) which is generallyrequired for stretched carpeting. The glued down carpeting avoidswrinkling without the need for stretching, but loses the benefit of acarpet pad. Also, the carpet can be very difficult to remove either forreplacement or temporarily, for maintenance, without destroying thefloor or the carpeting itself due to the adhesion of the glue.

In glue-down installations, the carpet is ordinarily laid on the floorfirst and seamed as required. The glue is then applied to the floor,either in liquid form or by spraying it onto the floor. This can beaccomplished by folding back half of the carpet, applying the glue tothe floor in that area, and dropping the carpet in place to adhere it tothe floor in that area. The opposite side of the carpet could then befolded back, glue applied to the floor in that area, and that portion ofthe carpet then adhered to the floor.

Another installation system wherein the carpet was adhered to the floorwithout padding is disclosed in U.S. Pat. No. 4,405,668 to Wald. Thissystem used a separate, thin scrim web with adhesive on both sides andwith a release film on one side. The scrim web was placed on a floorwith the release film on the upper surface, adhering the web to thefloor, whereupon the carpet could then be seamed and cut as requiredwhile lying on top of the release film. The carpet was then folded backand the release film removed in one area, that portion of the carpet waspressed down, and the operation was repeated in another area. Thissystem was relatively expensive and still did not permit theinstallation of a carpet pad beneath the carpeting. A similarconstruction of adhesive webbing material is shown in U.S. Pat. No.4,234,649 to Ward.

In yet another system for installing carpet without stretching, a slabor pad of jute material was interposed between the carpet backing andthe floor. In this particular system the floor was sprayed with a wetadhesive, the slab of jute material was laid into the adhesive while theadhesive was still wet, the top surface of the jute material was sprayedwith the wet adhesive, and the carpet was laid on the wet adhesive onthe top surface of the jute slab or pad. The wet adhesive, as it dried,became enough of a pressure sensitive adhesive to permit the carpet tobe pulled up and removed.

This system had the disadvantage of being an expensive system because ofthe costs required to make an on-the-job installation.

As noted above, U.S. Pat. No. 4,557,774 illustrates and discloses acarpet cushion and carpet-laying system similar to some aspects of thepresent invention, the principal difference being that in someembodiments of the present invention the cushion has apressure-sensitive adhesive preapplied to only one surface.

Water based pressure sensitive adhesives when applied to a carpetcushion are liquid, and will wick excessively into any porous surfacesuch as the porous surface of an untreated felt pad or rebonded urethanepad or of a porous remay which has often been used over a carpet cushionsurface. Consequently, some type of surface sealing is required for theuse of such adhesives, examples being a thin plastic skin adhered to theporous surface, or a sprayed-on sealant, or a crust formed at thesurface to seal the pad, as by heating. The need for such sealing isavoided in one aspect of the present invention described below.

SUMMARY OF THE INVENTION

It is a primary object of the present invention to hold carpet in placewithout stretching by a system that avoids the problems of the priorart.

It is a closely related object to hold the carpet in place by a systemthat utilizes a pad with pressure sensitive adhesive which is preappliedto one of the surfaces of the pad, with further adhesive applied on thejob, to the floor or the upper surface of the pad, depending on whichway the pad is used.

Another object, in a preferred embodiment, is the provision of a carpetcushion having hot melt pressure sensitive adhesive preapplied on one orboth surfaces, with the cushion surfaces being porous and unsuitable forwater based pressure sensitive adhesives in the absence of surfacesealants.

By the method of the present invention, carpeting is efficiently andeconomically installed without stretching or the need for tacklessstrips, but still with the benefit of a carpet cushion or pad betweenthe floor and the carpet.

In use of the one-sided adhesive coated carpet cushion of the invention,first there is positioned on the floor surface a carpet cushion having apressure-sensitive adhesive on one of its upper and lower surfaces. Thepreapplied adhesive may be down, against the floor, or up, forcontacting and holding the carpet in place, with a release film adheredto the adhesive on the upper surface. If the adhesive side is up, anadhesive may be first applied to the floor, as by troweling, spraying orrolling, before the cushion is laid down.

The carpet cushion need not include any significant stiffener, since theadhesion to the floor will provide needed dimensional stability.

When the cushion has been laid and trimmed as required, the carpet ispositioned on top of the release film (if the adhesive side is up) onthe carpet cushion, and rough cut and seamed as required. The carpet isthen folded back to expose a portion of the carpet cushion, usually onehalf, and the release film is removed from the exposed cushion.

The carpet is then pressed down onto the exposed pressure-sensitiveadhesive on the upper surface of the carpet cushion, and another portionof the carpet is folded back and the release film is removed from thatarea of the carpet cushion. That portion of the carpet is then presseddown.

If the adhesive side of the cushion is down, there is no need for arelease film and the carpet can be seamed and rough cut on the cushion'supper surface by sections, with the carpet folded back as describedabove.

When all areas of the carpet are in contact with the adhesive, finaltrimming of the carpet edges is performed.

The described method may include installing rigid spacer strips on thefloor along the walls of the room before laying the carpet cushion,preferably strips of wood or plastic with pressure-sensitive adhesive onboth sides. The purpose of the spacer strips is to provide an edgesimilar to that of the tackless strips, since the carpet installer'strimming tools have been designed to trim the carpet with the hard strippresent, cutting the carpet 1/4 inch long and tucking the carpet edgeunder, against the wall or baseboard. If a tackless strip from aprevious carpet installation is present, it may be left in place with noneed for the spacer strips.

In the manufacture of the carpet cushion, if a water-based pressuresensitive adhesive is used, sealing means preferably are applied to bothsurfaces of the pad, which may be a foam material, to substantially sealthe surface before the pressure-sensitive adhesive is added. This keepsthe adhesive at the surface of the foam or other material and preventswicking-in. The sealing means may comprise a thin corona treated orflame treated plastic skin adhered to each surface at the pad in themanufacturing process. Alternatively, it may comprise a liquid sealantapplied to the surfaces, or simply a crust formed at both the lower andupper surfaces of the foam cushion. A crust can be formed by a heatprocess, or by a curing process wherein increased density occurs at thesurfaces. A dense crust can eliminate the need for further sealing atthe surfaces of the foam.

The adhesive need not cover the entire surface of the carpet cushion,but may be in spaced strips. Adhesive cost is thereby reduced withoutadversely affecting the positional stability of the carpet installation.Also, this enables the carpet cushion to be stapled or tacked to thefloor, if needed in particular areas, in the spaces between strips ofadhesive when the adhesive is on the upper surface. The carpet will thenbridge the gap over the recess or dimple caused by the stapling, sincethere is no adhesive in this area.

The adhesive on the cushion's surfaces may be applied over the entirearea or it may be in parallel serpentine strips to discourage wrinklingof the carpet, which tends to occur in straight lines.

The system of the invention enables the use of less expensive carpetingthan usually required in stretch/tackless strip installations. Thetypical stretched carpet includes an upper surface yarn, extendingthrough a primary backing such as a polypropylene mesh, with a secondarybacking of a jute or polypropylene mesh for dimensional stability in thestretching operation.

With the present system of adhesive bonding of the carpet to the pad andthe pad to the floor, the carpet does not need an expensive secondarybacking, since it is adhered down in substantially all areas and is notstretched.

In the manufacture of carpet cushions according to the invention using ahot melt pressure sensitive adhesive, sealing means are not required onthe surface or surfaces of the porous pad prior to application of theadhesive. Further, the padding material may comprise inexpensive scrapmaterials of natural or synthetic material. This can include felt orsynthetic felt or rebonded urethane scraps, all of which have extremelyporous surfaces which would cause excessive wicking-in of a water basedpressure sensitive adhesive.

The porous carpet pad is formed in sheet-like form, in such thickness,density and compressibility to serve as a carpet cushion. Onto thissheet of carpet padding is applied a hot melt pressure sensitiveadhesive, on at least one surface. The hot melt pressure sensitiveadhesive is applied at a somewhat elevated temperature, above the flowjoint temperature of the hot melt pressure sensitive adhesive.Immediately upon coming into contact with the porous surface of thecarpet cushion sheet, the hot melt pressure sensitive adhesive liessubstantially entirely on the surface, adhering strongly to theextremity of the porous surface in a non-flowable state. The adhesivedoes not appreciably wick into the porous carpet pad surface.

The hot melt pressure sensitive adhesive may be applied as described toboth surfaces of the carpet pad. Optionally, a scrim webbing may beapplied over the hot melt pressure sensitive adhesive layer. The scrimadheres to the adhesive but tends to space the adhesive slightly awayfrom a floor or other surface, so that the carpet pad with the adhesivedoes not appreciably adhere to the floor until deliberate pressure isapplied. The scrim webbing also adds dimensional stability, needed withcertain carpet cushion materials.

It is therefore among the objects of the invention to improve on priorcarpeting installation systems and carpet pads by providing a carpetcushion or pad having pressure sensitive on at least one surface, foradhering to the floor or the carpet to the upper surface of the cushionwith adhesive applied on the job for the other surface, avoiding theneed for stretching or relatively expensive carpeting which includes asecondary backing. A related object is the provision of a carpet cushionwith preapplied hot melt pressure sensitive adhesive, on a paddingmaterial which is very porous and unsealed and which may be formed ofinexpensive scrap materials, greatly reducing the cost of the carpetcushion. The hot melt pressure sensitive adhesive may be applied to oneor both sides of the cushion.

Other objects, advantages and features of the invention will be apparentfrom the following description of preferred embodiments, consideredalong with accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary sectional view showing a carpet and padinstalled with the carpet pad of the invention.

FIG. 2 is a perspective view stowing a carpet pad according to theinvention and comprising a part of the installation shown in FIG. 1. Thepad is shown coming off a roll, with a release film covering one side ofthe adhesive coated pad on the inside of the roll, in accordance withone embodiment of the invention.

FIG. 3 is a perspective view showing a floor in preparation for carpetinstallation according to the invention, with the pad laid on the floorand the carpet being unrolled on top of the pad.

FIG. 4 is a perspective view similar to FIG. 3, but showing the carpetpulled back for peeling away the release film from the top surface ofthe pad, in a portion of the floor where the carpet, already seamed andcut, has been pulled or rolled back. In this embodiment of the system ofthe invention the cushion is installed with adhesive side up forcontacting the underside of the carpet.

FIG. 5 is a plan view showing a pad according to the invention with itspressure-sensitive adhesive applied in parallel strips rather than overthe entire surface of the pad, and showing optional stapling between thestrips of adhesive.

FIG. 6 is a plan view similar to FIG. 4, but showing the adhesiveapplied in serpentine strips.

FIG. 7 is a schematic view indicating a method for producing the carpetpad of the invention.

FIG. 8 is a view like FIG. 4 but showing the cushion installed with theadhesive side down. An adhesive is then applied to the upper side of thecushion prior to engaging the carpet back to that side of the cushion.The adhesive is applied by troweling in FIG. 8.

FIG. 9 is a fragmentary sectional view showing a carpet cushion inaccordance with another embodiment of the present invention, with hotmelt pressure sensitive adhesive applied to one or both sides.

FIG. 10 is a schematic view indicating a method of manufacturing acarpet cushion having hot melt pressure sensitive adhesive on one orboth sides.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the drawings, FIG. 1 shows a carpet 10 with a pile 11 and a singlebacking layer or primary backing 12 laid on a pad or carpet cushion 13comprising a pad 14 which may be of foam material, with a skin, crust orsealant 16 on both surfaces of the pad and a pressure-sensitive adhesivelayer 17 on one of the top and bottom surfaces of the pad 14, applied tothe skin, crust or sealant 16. In accordance with the invention theskin, crust or sealant 16 may be eliminated when a hot melt pressuresensitive is used, on one or both surfaces. This is discussed furtherbelow.

In FIG. 1 the adhesive layer is shown on the upper surface of the pad13. In this embodiment the adhesive 17 holds the carpet backing 12 tothe carpet cushion 13. If the adhesive surface is down, on the otherhand, it holds the carpet cushion to the surface of the floor 18 below.Installation steps with respect to these two orientations of the carpetcushion 13 are described further below.

FIG. 2 shows a roll 19 of the carpet cushion 13 of the invention,showing the pad 14 (which may be urethane, rubber or felt) and the uppersealed surface 16. The adhesive layer 17 is shown on the upper surfaceas the cushion 13 will be unrolled, although it can be on the lowersurface. A release film 21 of a sheet plastic material is shownoverlying the upper surface of the carpet cushion 13, i.e., the innersurface of the cushion on the roll 19, being temporarily adhered to thatsurface. The bottom of the cushion 13, and thus the outer surface of theroll 19 as seen in FIG. 2, need not be covered by any release film,unless the adhesive side is outside, in which case an outer cover isused until the roll reaches the job site.

The release film (covering the pressure sensitive adhesive the uppersurface of the padding as shown in FIG. 2) enables the cushion to belaid on a floor and adhered to the floor while still leaving the uppersurface usable as a work surface for unrolling the carpet 10 andperforming preliminary cutting and seaming operations as necessary. Forstorage and transport of the roll 19 prior to installation, the releasefilm may have a tail or extension 20 (dashed lines) which wraps aroundthe roll and covers the exposed adhesive.

FIG. 3 illustrates some aspects of the installation operation accordingto the system of the invention. First, rigid spacer strips 22 may beinstalled around the edges of the room near the walls 23. The spacerstrips 22 may be of wood or plastic, for example, with apressure-sensitive adhesive 24 either preapplied onto both the upper andlower surfaces of the strips or applied on the job to both the upper andlower surfaces. The purpose of the strip 22 is merely to take the placeof the conventional tackless strips, in the sense that conventionalcarpeting tools for trimming the finished carpet have been designed tobe used along the edges of the tackless strips. If tackless strips arein place from a prior carpet installation, they can be left intact, andthe spacer strips 22 would then not be needed.

It should also be understood that the carpet installation according tothe invention may be performed without the use of any spacer strips 22or tackless strips provided the installer uses tools adequate toproperly trim the carpet without the presence of the usual rigid strip.

If the floor surface is dusty, a floor primer can be used to lock thedust particles to the floor, creating a better bonding surface.

The carpet cushion 13 is unrolled onto the floor along the spacer strips22, which are of about the same thickness as the cushion, generally inthe manner shown in FIG. 2.

FIG. 3 shows the adhesive carpet cushion 13 laid and trimmed on thefloor 18, with its lower side adhered to the floor 18.

If the preapplied pressure sensitive adhesive side is up, as illustratedin FIG. 3, a suitable layer of glue (pressure-sensitive or non-pressuresensitive adhesive) 20 is applied to the floor surface, as by troweling,spraying or rolling before the cushion 13 is unrolled onto the floor.

After the cushion has been laid and trimmed, the release film 21 is leftin place on the upper surface as shown in FIG. 3.

The carpet 10 is then unrolled over the top of the release film, andseaming and preliminary cutting are performed as necessary.

With the carpet seamed (carpet seaming is indicated at 25) and rough cutit is then folded back or rolled back as indicated in FIG. 4 to expose aportion 13a of the cushion. This enables the release film 21 to bepeeled off the upper surface of that portion of the cushion 13a asindicated in FIG. 4. Once this is accomplished, the carpet is put backinto position on the sticky upper surface of the cushion portion 13a;and the same operation is then repeated with another portion of thecarpet 10 which may be the other half of the room. That is, the carpetis pulled or folded or rolled back to expose another portion of theremainder of the carpet cushion and its release film 21 is peeled off.Then the remaining portion of the carpeting is moved back into position,until all areas of the carpet are in contact with the upper surface ofthe carpet cushion, and final trimming operations are conducted.

If, on the other hand, the preapplied adhesive surface is laid downagainst the floor, then a similar operation is performed with respect topulling back portions of the carpet, but there is no release film 21 toremove since there is no preapplied adhesive on the upper side of thecushion. Therefore, when a section of carpet is pulled back apressure-sensitive or non-pressure sensitive adhesive is applied to thecushion by spraying or troweling. The adhesive may be a water basedpressure sensitive (e.g. acrylic) or a hot melt pressure sensitiveadhesive, or any other suitable adhesive. FIG. 8 shows such an adhesive25 being applied to the upper surface of the cushion using a trowel 28.

In one aspect of the invention, the adhesives used in some embodimentsof the carpet cushion and method of the invention are water based, andmay comprise an acrylic water based adhesive which loses its tackinesswhen wetted but regains tackiness upon drying. For example, the adhesivemay be the product Flexcryl 1625 marketed by Air Products Company. Boththe preapplied adhesive and the adhesive added on the job can comprisethis type of adhesive. One advantage of this type of adhesive is itsability to regain its tackiness after being over soaked with water. Inthis sense, the adhesive is non-permanent and allows for temporarylifting of the carpet when desired.

Once the carpet and cushion dry, the adhesive regains its tackiness andthe carpet can be pressed into the adhesive.

The invention enables a less expensive water base latex non-pressuresensitive type adhesive or a multi-purpose adhesive to be used on thejob site, either trowelled or rolled on the floor or upper surface ofthe cushion.

FIG. 5 shows a carpet cushion 13b according to the invention, withspaced strips of adhesive 17a upon the surface, separated by spaces 26on the surface which have no adhesive. This saves on the amount ofadhesive required while still providing for adequate adhesion of thecarpet cushion 13b to the floor or the carpet backing. Also, when theadhesive is up, it enables staples 27 or tacks to be used to hold thecarpet cushion 13b down to the floor if required under specialcircumstances, without causing the carpet to recess or "dimple" inwardlyat the location of the staple. Dimpling is avoided because there is noadhesive in the immediate vicinity of each staple 27, so the carpet doesnot adhere into the recess in the cushion caused by the staple, butrather the carpet bridges across the recess.

FIG. 6 shows a serpentine pattern for adhesive strips 17b on a carpetcushion 13b, which may be desired to prevent a pattern of wrinkling inthe installed carpet. Wrinkles tend to occur in straight lines, so thatthe serpentine pattern shown in FIG. 6 discourages the occurrence ofwrinkles.

As indicated in FIG. 7, in the manufacture of the adhesive carpetcushion 13, a very thin plastic film or skin may be bonded to or formedon both sides of the foam sheet 14 in the manufacturing process, to formthe sealing surface 16 described above. The skin 16 may be bonded to thesurfaces of the pad 14 by a corona-heat bonding process, so that it isfused into the surfaces of the pad during the manufacturing process (asby a hot roller), or it may be bonded by other suitable means such asadhesives. A skin or crust may be formed (as an integral part of thecushion) as part of the forming process of manufacturing a foamedcushion. It may be formed by heat applied to a foam surface.Alternatively, a sealant 31 may be applied in lieu of the plastic skin,or integral crust, as by liquid application or spraying by spray nozzles32 on both surfaces of the pad. In either event, the surfaces are sealedto substantially close the porosity of the foam at the surfaces.

Next, a pressure sensitive adhesive 17, either hot melt or water based,is applied to at least one surface, as by sprayers 33 (or by rollers,not shown), and the adhesive does not penetrate into the foam. The priorapplication of the sealing means prevents this, in the case of a waterbased adhesive, but it should be understood that the sealing means canbe eliminated if a hot melt pressure sensitive adhesive is used.

As mentioned above, the sealing means, if needed, may alternativelycomprise a crust of substantially increased density in the surfaces ofthe foam pad, formed by heat, the manner of curing of the foam, or othersuitable means.

The release film 21 may next be applied to one side of the carpetcushion 13, temporarily bonding to the adhesive on that side.Preferably, all of these operations are accomplished in a continuousprocess wherein the foam 14, sealing film 16 and release film 21 areadvanced off roll stock 16a and 21a as schematically indicated in FIG.7. The sealant and adhesive are applied at appropriate points in theoperation, and the final product emerges complete and is store in rolls19 similar to that shown in FIG. 2. If the sealing film 16 is heated bya hot roller on application (for good bonding), roller temperature iscritical. If heated to too high a temperature the skin will developpinholes. Choice of skin materials is important--some skins will betterwithstand heat.

A scrim webbing 35 (dashed lines) may be applied over the adhesive layer17, if desired. As discussed above, the scrim webbing adds furtherdimensional stability and also spaces the adhesive 17 slightly away fromthe floor or carpet backing, so that the cushion (or the carpet) may bemore easily moved around before tacking it down by pressure. The scrimmust be open enough, and of sufficiently fine filaments, that the padwill bond to the floor (or carpet backing) when pressure is applied. Aminimum of about 1/4 opening size, and a fine filament size, should beused so that the scrim does not hold the adhesive too strongly away fromthe floor. The scrim opening size and filament size depend to someextent on the pad's surface coarseness, with coarser pads not requiringas fine a filament size or as large openings.

The cushion or padding 13 can also be made from materials other thanintegrally formed foam. For example, the cushion may be made fromrebonded urethane, rubber or felted needle punched synthetic with sealedsurfaces on the top and bottom, in the event water based pressuresensitive adhesive is used.

As discussed above, another very important aspect of the presentinvention is a carpet cushion or pad of the general type described, butspecifically with a hot melt pressure sensitive adhesive applied to oneor both sides of an otherwise porous pad surface. FIG. 9 showsschematically such a carpet cushion 38. The cushion 38 may be formed ofa sheet of carpet padding material 39 which is of low cost materials andwith porous surfaces, such as would not generally be practicable for usewith a water based pressure sensitive adhesive unless a surface sealingmeans were applied, as discussed above. In this embodiment, the poroussurfaces of the pad 39 preferably are left porous, without any treatmentfor sealing them. A hot melt pressure sensitive adhesive 41 is appliedto one or both sides of the porous pad 39. Due to the nature of the hotmelt pressure sensitive, it can be applied either by spraying or byextruding onto the surfaces, and it will adhere to the porous surfacesin a non-flowable state, such that it cannot wick into the cushion 39 toany appreciable degree. Sealing means such as liquid sealants or plasticskins or heat formed crusts may be used prior to application of theadhesive if desired, but they are not necessary.

The material of the sheet of carpet padding 39 may comprise inexpensiverebonded urethane scraps, for example, or it may comprise a natural orsynthetic felt or cotton material or rubber. The pad 39 may comprise aurethane or other foam material to which has been applied a remay, afuzzy layer which is usually intended to hold an adhesive (e.g. aspun-bonded non-woven nylon or polyester). Even in the presence of arelatively thick remay covering, the hot melt pressure sensitiveadhesive 41 will not appreciably wick into the remay and can be usedvery efficiently in producing the carpet cushion 38. The hot meltpressure sensitive adhesive remains in a semi-solid, nonflowable state,and it is aggressively tacky when pressed into contact with a floor orcarpet padding or other surface.

The hot melt pressure sensitive adhesive may be of several types, suchas a non-permanent, semi-permanent or permanent adhesive, such asmanufactured by Fuller Corporation.

As shown in the schematic diagram of FIG. 10, the hot melt pressuresensitive adhesive material 41 may be applied to the carpet paddingsheet or base 39 by extruding it (extruders 42) onto the surface orsurfaces (or it can be applied by spraying). As discussed above inconnection with FIG. 7, a scrim webbing 45 (dashed lines) may be appliedto one or both surfaces, on top of the hot melt pressure sensitiveadhesive. This can add dimensional stability, particularly in the caseof inexpensive felt-like materials or urethane materials which areotherwise not very dimensionally stable. It also helps in manipulationof the carpet pad 38 during the installation procedure, in allowing itto slide around against other surfaces without significant sticking, dueto the scrim webbing's spacing of the adhesive away from the surface towhich it will ultimately adhere. Again, as discussed above, the filamentsize and opening size of the scrim must be selected (depending on thecoarseness of the pad surface) to permit good bonding of the pad to thefloor (or carpet).

FIG. 10 also shows an arrangement wherein a release film 21 is appliedfrom a roll 48 to one side of the cushion, onto the hot melt pressuresensitive adhesive on that side. The release film 21 thus enables thecushion 38 to pass over rollers 49 and 50, enroute to a storage roll 51for the completed cushion assembly 38.

The hot melt pressure sensitive adhesive may also be advantageouslyapplied to the padding material 39 by spraying. It may be sprayed ontothe surfaces using hot melt spray equipment such as manufactured bySlautterback Corporation of Monterey, Calif. Such adhesive may have aflow point of about 300° F., although the specific flow pointtemperature is not as important as the feature that the adhesive beessentially non-flowable and aggressively tacky at room temperature andmoderately above room temperature, and that it be capable of coolingquickly to such state upon contacting the porous surface. Hot meltpressure sensitive adhesives are available in a wide range of flow pointtemperatures.

As an alternative to the adhesive application methods discussed aboveand indicated in FIG. 10, the hot melt pressure sensitive adhesive maybe applied to the pad surface by transfer coating. By this process, thehot melt pressure sensitive adhesive is first applied to a release film(such as the release film 21), then the film is applied to the pad sheetsuch that the adhesive contacts the pad surface. When removed, therelease film leaves the adhesive on the pad surface.

It should be understood that the carpet pads of the invention, in thevarious forms described above, can be used to lay a new carpet over anexisting carpet, without removal of the existing carpet. The carpetcushion of the invention, for example the two-sided hot melt pressuresensitive adhesive-coated cushion such as shown in FIG. 9, may be laidon top of the surface of the existing carpeting. New carpet may then beinstalled on the upper surface of the carpet cushion 38. Such aninstallation saves greatly on installation time and cost, and providesfurther cushioning for the carpet.

The carpet pad of the invention may also form a part of a combinationcarpet/pad product wherein the pad is permanently adhered to theunderside of a carpet, for combined installation. The hot melt pressuresensitive adhesive is on the bottom surface of the pad or cushion.

The above described preferred embodiments are intended to illustrate theprinciples of the present invention, but not to limit its scope. Otherembodiments and variations to these preferred embodiments will beapparent to those skilled in the art and may be made without departingfrom scope of the invention as defined by the following claims.

I claim:
 1. A method for forming a carpet cushion having preappliedpressure sensitive adhesive on at least one surface, comprising,forminga carpet pad in sheet-like form, the carpet pad being of such thickness,density and compressibility to serve as a carpet cushion, applying ontothe sheet of carpet pad a hot melt pressure sensitive adhesive on atleast one surface of the carpet pad, said one surface being porous,unsealed, and of a strong liquid wicking characteristic such that aliquid pressure sensitive adhesive would wick into the surface to anobjectionable extent, including the step of applying the hot meltpressure sensitive adhesive at an elevated temperature, above the flowpoint temperature of the hot melt pressure sensitive adhesive, andincluding controlling the temperature of the hot melt pressure sensitiveadhesive during applying of the adhesive such that the adhesive coolssomewhat on contact with the carpet pad and congeals onto and stronglyadheres to the extremity of the porous surface of the carpet pad, to anextent that the hot melt pressure sensitive adhesive substantially doesnot wick into the porous carpet pad surface.
 2. The method according toclaim 1, wherein the hot melt pressure sensitive adhesive is extrudedonto and adhered to both surfaces of the carpet pad.
 3. The methodaccording to claim 1, wherein the carpet pad is made up of scrapmaterials.
 4. The method according to claim 1, wherein the hot meltpressure sensitive adhesive is extruded onto the surface of the carpetpad.
 5. A carpet cushion with pressure sensitive adhesive, formedaccording to the method of claim
 4. 6. A method for forming a carpetcushion having preapplied pressure sensitive adhesive on at least onesurface, comprising,forming a carpet pad in sheet-like form, the carpetpad being of such thickness, density and compressibility to serve as acarpet cushion, spraying onto the sheet of carpet pad a hot meltpressure sensitive adhesive at an elevated temperature, above the flowpoint temperature of the hot melt pressure sensitive adhesive, on atleast one surface of the carpet pad, said one surface being porous,unsealed, and of a strong liquid wicking characteristic such that aliquid pressure sensitive adhesive such as a water based pressuresensitive adhesive would wick into the surface to an objectionableextent, controlling the temperature of the hot melt pressure sensitiveadhesive such that it contacts the porous surface of the carpet pad in asubstantially non-flowable state, congealing onto the adhering stronglyto the porous surface of the carpet pad but not wicking into poroussurface to any appreciable degree.
 7. A carpet cushion with pressuresensitive adhesive, formed according to the method of claim 6.